Protein product and process for preparing injectable protein product

ABSTRACT

Moisture is retained in cooked or thawed food by adding to the food an aqueous suspension of animal muscle protein obtained from animal muscle tissue. The aqueous suspension is obtained by mixing comminuted animal muscle tissue with a food grade base to form an aqueous basic solution of animal muscle protein. The basic solution is mixed with a food grade acid to precipitate the protein in an aqueous composition. The precipitated protein then is comminuted to form an aqueous suspension of comminuted animal muscle protein.

REFERENCE TO RELATED APPLICATION

This application is a continuation of co-pending application Ser. No.12,924,382 filed Sep. 27, 2010 which application is acontinuation-in-part of co-pending application Ser. No. 12/798,423,filed Apr. 5, 2010.

BACKGROUND OF THE INVENTION

This invention relates to a novel protein composition derived fromanimal muscle tissue, a process for making the protein composition andto a process for retaining moisture in food, cooked or uncooked.

At the present time, it is desirable to retain moisture in cooked oruncooked food so that drying of the food during the cooking process isminimized. It is also desirable to retain moisture in cooked or uncookedfood so that the natural food flavors are retained in the food evenafter cooking.

A common occurrence of moisture loss occurs when a frozen food is thawedsuch as prior to cooking the food. The thawed food experiences drip losswherein a liquid aqueous composition such as water is formed and becomesseparated from the solid thawed food.

A second common occurrence of moisture loss occurs when an uncooked foodis cooked. Liquid moisture in the food becomes vaporized during thecooking process and migrates to the food surface where it evaporates orseparates as a liquid from the solid food being cooked.

At the present time, a variety of additive compositions are added tofood, primarily by injection, by vacuum tumbling and/or with syringes.Prior attempts to retain moisture in cooked meat or fish with additiveshave included the use of sodium tripolyphosphate, starches, vegetablefibers, a coating of fat free flour based batter containing an egg whitesubstitute (U.K. Patent Application 2,097,646), water-in-oil emulsion(U.S. Pat. No. 3,406,081), protein or protein isolate and a fat (U.S.Pat. Nos. 4,031,261 and 4,935,251), milk solids (U.S. Pat. No.2,282,801) and lecithin (U.S. Pat. Nos. 2,470,281 and 3,451,826).

An example of such a composition also is disclosed in U.S. Pat. No.6,855,364 wherein an acidic protein composition derived from animalmuscle tissue is added to a food prior to cooking in order to retainmoisture in the food during cooking. The acidic protein composition isone obtained by mixing a food grade acid composition with comminutedanimal muscle tissue to obtain an acidic protein composition. Suitableprocesses for obtaining the acidic protein composition are disclosed inU.S. Pat. Nos. 6,005,073; 6,288,216; 6,451,975 and/or 7,473,764 all ofwhich are incorporated herein by reference in their entirety. U.S. Pat.Nos. 6,136,959 and 7,556,835 disclose processes for solubilizing animalmuscle tissue with an alkaline composition which are incorporated hereinby reference in their entirety.

Accordingly, it would be desirable to provide a form of fish or meatwhich can be thawed and/or cooked while retaining its moisture andnatural flavors or added flavors. In addition, it would be desirable toprovide such a form of fish or meat wherein the majority of moisture oradded flavors in the uncooked fish or meat is retained during cooking.

SUMMARY OF THE INVENTION

In accordance with this invention, it has been found that a novel animalmuscle protein composition comprising sarcoplasmic proteins andmyofibrillar proteins derived from animal muscle tissue provide improvedmoisture retention in food being thawed or cooked. The animal muscleprotein composition is obtained from animal muscle tissue by comminutingthe animal muscle tissue and then mixing it with a food grade alkalinecomposition under conditions to solubilize the animal muscle proteinthereby forming a solution of animal muscle protein. The solubilizedbasic animal muscle tissue then is mixed with a food grade acidcomposition to decrease the pH of the solubilized animal muscle proteinto a pH between about 4.7 and about 11.0, preferably between about pH5.5 and about 9.5, thereby to precipitate the protein. The precipitatedprotein then is comminuted to form protein particulates suspended in anaqueous medium. It has been found that when the animal muscle proteincomposition prepared by the process of this invention is added to a foodto be thawed and/or cooked, increased moisture retention in the food isobserved as compared to an acidic animal muscle tissue proteincomposition or an alkaline animal muscle tissue protein compositionobtained without the first step of forming a basic animal musclecomposition formed from animal muscle tissue.

This result is surprising since the protein compositions are chemicallythe same. While applicants do not wish to be bound to any theoryexplaining this surprising result, it is believed that by first mixingthe animal muscle tissue with a food grade base, unfolding or expandingof the protein molecules is promoted and the subsequent mixing of theprotein with a food grade acid compound results in an increase infunctionality of the protein. This increase in functionality promotesincreased moisture retention in the food being treated with the protein.

In addition, it has been found that the comminuted animal muscle proteincomposition of this invention can be injected into food when pumpedthrough a syringe while avoiding protein precipitation within thesyringe which blocks the fluid pathway through the syringe. In contrast,it has been found that when the precipitated protein which has beenmixed first with a base and then with an acid but is not comminutedblocks the fluid pathway of a syringe within seconds after pumping ofthe protein composition is initiated. In addition, it has also beenfound that when the precipitated protein which has been mixed first witha base and then with an acid and additionally mixed with salt, forflavoring, and then comminuted does not block the fluid pathway of thesyringe. This is not true for proteins held at the low pH or proteinsthat go directly to high pH in contrast to proteins that are adjusted tohigh pH prior to adjustment to a low pH. Also, in contrast to thecomposition of this invention, animal muscle tissue which has beensolubilized with an alkaline composition to form basic animal muscleprotein which is comminuted or not comminuted blocks the fluid pathwayof a syringe within seconds after initiating pumping through thesyringe. The fact that these protein compositions block the fluidpathway through the syringe renders them useless for injecting a foodwith a syringe. In addition, the protein composition mixed first with abase and then with an acid and not comminuted or is mixed only with abase and comminuted or not comminuted can not be adequately injectedinto a food by vacuum tumbling since they are retained on the surface ofthe food and do not satisfactorily penetrate the food surface.

The animal muscle protein composition of this invention can be derivedfrom any form of animal muscle tissue including that obtained from fish,poultry such as chicken, shellfish such as shrimp, lamb, beef, pork orthe like.

When moisture is to be retained in food to be thawed and/or food to becooked, the protein composition of this invention is first added to thefood including mixing the protein composition with the food or injectingthe protein composition into the food such as by vacuum tumbling and/orwith a syringe.

DESCRIPTION OF SPECIFIC EMBODIMENTS

In accordance with this invention, in a first step, the basic muscletissue protein comprising sarcoplasmic proteins and myofibrillarproteins is formed by comminuting animal muscle tissue and then mixingthe comminuted animal muscle tissue with a food grade alkalinecomposition under conditions to solubilize the animal muscle tissue.Sufficient water also is added to the tissue to fully disperse it. Thewater and alkaline composition can be added in sequence or addedtogether with the tissue. The resultant basic animal muscle tissueprotein solution has a pH of about 10.5 or greater, preferably betweenabout 11.0 and about 12.5, most preferably between about 11.5 and about12.0 but not so high as to adversely affect the protein functionality.

Any food grade or pharmaceutically acceptable base that does notundesirably contaminate the basic protein product can be used to raisethe pH of the protein product. For example, representative suitablealkaline compositions include sodium hydroxide, potassium hydroxide,sodium bicarbonate, potassium bicarbonate or mixtures thereof or thelike. The animal muscle tissue is formed into small tissue particleswhich are then mixed with sufficient base to form a solution of thetissue having a pH of 10.5 or higher, but not such a high pH as toadversely modify the animal muscle tissue protein. In one process, thesolution is centrifuged to form a lowest membrane lipid layer, anintermediate layer of aqueous basic protein solution and a top layer ofneutral lipids (fats and oils). The intermediate layer of aqueousalkaline protein solution then is separated from the membrane lipidlayer or from both the membrane lipid layer and the neutral lipid layer.In a second process, no centrifugation step is effected since thestarting animal muscle tissue contains sufficiently low concentrationsof undesired membrane lipids, oils and/or fats as to render acentrifugation step unnecessary. In both processes, the proteincomposition formed is free of myofibrils and sarcomeres.

The basic animal muscle protein solution then is mixed with a food gradeor pharmaceutically acceptable acid composition to lower the pH of thebasic solution to a pH of between about 4.7 and about 11.0, preferablybetween about 5.5 and about 9.5 to precipitate the animal muscleprotein. Representative suitable organic acids include citric acid,ascorbic acid, malic acid or tartaric acid or mineral acids such ashydrochloric acid, phosphoric acid, sulfuric acid or mixtures thereof.The precipitated animal muscle protein then is comminuted into fineparticles such as with apparatus having one or more rotating blades orone or more reciprocating blades thereby to form an aqueous suspensionof animal muscle proteins.

The aqueous suspension of animal muscle protein is admixed withcomminuted meat or whole fish, fish fillets, whole pieces of meat orinjected into meat or fish. Injection can be effected in any manner suchas with a syringe or by vacuum tumbling or both. It has been found thatwhen the resultant meat or fish is thawed or the resultant meat or fishis cooked, the thawed or cooked meat or fish retains significantlygreater moisture as compared to meat or fish not containing the proteincomposition of this invention.

The protein products utilized in the present invention compriseprimarily myofibrillar proteins that also contain significant amounts ofsarcoplasmic proteins. The sarcoplasmic proteins in the protein productadmixed with or injected into the animal muscle tissue comprises aboveabout 8%, preferably above about 10%, more preferably above about 18%,up to about 30% by weight sarcoplasmic proteins, based on the totalweight of protein.

In one aspect of this invention, particulate meat or fish such as groundmeat or fish, e.g., hamburger, is mixed with the protein suspensioncomprising myofibrillar proteins and sarcoplasmic proteins at a weightratio usually comprising about 0.03 to about 18% weight of the proteinmixture based on the weight of the uncooked meat or fish, preferablybetween about 0.5 and 10% weight based on the weight of uncooked meat orfish and most preferably comprising between about 0.5 to about 5% weightbased on the weight of the uncooked meat of fish. When utilizing lessthan about 0.3% weight of the protein suspension of this invention,effective moisture retention is not observed.

The animal muscle tissue which is modified to retain moisture inaccordance with this invention comprises meat and fish, including shellfish. Representative suitable fish include deboned flounder, sole,haddock, cod, sea bass, salmon, tuna, trout or the like. Representativesuitable shell fish include shrimp, crabmeat, crayfish, lobster,scallops, oysters, or shrimp in the shell or the like. Representativesuitable meats include ham, beef, lamb, pork, venison, veal, buffalo orthe like; poultry such as chicken, mechanically deboned poultry meat,turkey, duck, goose or the like either in fillet form or in ground formsuch as hamburger. The meats can include the bone of the animal when thebone does not adversely affect the edibility of the meat such as spareribs, lamb chops or pork chops. In addition, processed meat productswhich include animal muscle tissue such as a sausage composition, a hotdog composition, emulsified product or the like can be injected or mixedwith the protein suspension of this invention or a combination of theseprotein addition methods. Sausage and hot dog compositions includeground meat or fish, herbs such as sage, spices, sugar, pepper, salt andfillers such as dairy products as is well known in the art.

The fish or meat containing the protein suspension of this inventionthen can be cooked in a conventional manner such as by baking, broiling,deep fat frying, in a microwave oven or the like. It has been found thatthe cooked meat or fish provided in accordance with this inventionweighs between about 1 and about 20%, more usually between about 4% andabout 9% by weight greater than cooked untreated meat or fish startingfrom the same uncooked weight. In addition, when frozen meat or fishcontaining the protein suspension is that drip loss from the food isreduced between about 4 and about 15% as compared with meat or fish notcontaining the protein suspension of this invention.

The following example illustrates the present invention and is notintended to limit the same.

EXAMPLE 1

This example illustrates that the protein composition made by the methodof this invention provides an improved increase in moisture retention infish or shellfish as compared to acidic basic protein composition notmixed with an acid composition. The basic protein compositions shown inTable 1 were processed by mixing comminuted fish muscle protein with afood grade alkaline composition comprising sodium hydroxide to obtain aprotein solution having a pH of 12.0. The protein composition of thisinvention were obtained by mixing comminuted chicken muscle protein witha food grade alkaline composition comprising sodium hydroxide to obtaina pH of 12.0 in a first step. In a second step, a food grade acidcomposition comprising 2 M hydrochloric acid was added to the basicprotein solution to precipitate the protein having a pH of 4.7 Theprecipitated protein in each instance was comminuted with a Stephanmicro-cut apparatus having two rotating blades to form a suspension ofprotein and an aqueous medium having pH values shown in Table 1.Additional adjustments in pH above pH 4.7 as shown in Table 1 wereaccomplished using sodium hydroxide. The protein composition made frommuscle protein as described herein was injected into the chicken muscletissue and placed into a vacuum tumbler for 20 minutes with a vacuum of24-24 mm Hg. The injected animal muscle tissue was then allowed tosettle for 20 minutes prior to determining pick-up weights. The controlinjection marinade was a solution of salt (2.0%), sodiumtripolyphosphate (3.0%) and cold water (95%). This phosphate/brinesolution is standard in the industry. All injected product was baked ina convection oven until an internal temperature of 165° F. was achieved.The animal muscle tissue samples were weighed prior to injection,subsequent to injection and subsequently to being baked.

As shown in Table 1, moisture retention as pick-up and cook yields wereimproved with the with the protein compositions of this invention whencompared to the STPP/Brine controls and the alkaline adjusted (pH 12)protein with no further pH adjustments.

TABLE 1 Injection Retention and Cook Losses for Chicken Breasts Pre-Injection/ Post- Tumble Injection/ INJECTION (Green) Tumble Pick-up &TUMBLE Muscle Type Weight (g) Weight (g) Weight (g) Pick-up ControlChicken 334.00 377.00 43.00 12.87% (STPP/Salt) pH 12 Chicken 713.24806.81 93.57 13.12% pH 12 → pH Chicken 578.54 658.45 79.91 13.81% 4.7 pH12 → pH Chicken 562.38 643.11 80.73 14.36% 7.5 Pre-Cook Post-Cook CookLoss Cook COOK Muscle Type Weight (g) Weight (g) (g) Loss ControlChicken 377.00 270.00 107.00  28.38% (STPP/Salt) pH 12 Chicken 256.92185.42 71.50 27.83% pH 12 → pH Chicken 327.10 245.06 82.04 25.08% 4.7 pH12 → pH Chicken 288.08 212.60 75.48 26.20% 7.5

1. An injectable salted aqueous suspension of functional animal muscletissue protein composition for use during a food processing injectionprocedure with at least one injection pathway wherein said saltedaqueous suspension of functional animal muscle tissue comprisessarcoplasmic proteins and myofibrillar proteins derived from animalmuscle tissue obtained by the process comprising the steps of: A)comminuting animal muscle tissue to form comminuted animal muscletissue, B) mixing said comminuted animal muscle tissue with a food gradealkaline composition to solubilize animal muscle protein in an aqueousbasic solution of animal muscle protein having a pH between about 10.5and about 12.5, C) preparing an aqueous suspension of animal muscleprotein by mixing said aqueous basic solution with a food grade acidcomposition to precipitate the animal muscle protein in solution to forman aqueous suspension of animal muscle protein particulates having a pHbetween about 4.7 and about 11.0, D) adding salt to said aqueoussuspension thereby to form a salted aqueous suspension of animal muscleprotein, and E) comminuting said salted aqueous suspension of animalmuscle protein to form the injectable salted aqueous suspension offunctional animal muscle tissue protein including sarcoplasmic proteinsand myofibrillar proteins whereby said comminuted salted aqueoussuspension flows through each injection pathway during an injectionprocedure without blocking an injection pathway.
 2. The composition ofclaim 1 wherein the animal muscle tissue is taken from the groupconsisting of: i) fish animal muscle tissue, ii) shellfish animal muscletissue including shrimp animal muscle tissue, iii) poultry animal muscletissue including chicken animal muscle tissue and turkey animal muscletissue, and iv) meat animal muscle tissue including beef animal muscletissue, pork animal muscle tissue and lamb animal muscle tissue.
 3. Thecomposition of claim 1 wherein the pH of the aqueous basic solution isbetween about 11.0 and about 12.5.
 4. The composition of claim 1 whereinthe pH of the aqueous suspension of animal muscle protein is betweenabout 5.5 and about 9.5.
 5. The process for retaining moisture in animalmuscle tissue which comprises: A) adding the injectable salted aqueoussuspension of functional animal muscle tissue protein composition ofclaim 1 to said animal muscle tissue whereby said salted aqueoussuspension of functional animal muscle tissue protein composition isinjected into said animal muscle, and B) cooking or thawing said animalmuscle tissue with said injectable salted aqueous suspension offunctional animal muscle tissue protein composition from step (a). 6.The process of claim 5 wherein the injection of the salted aqueoussuspension of functional animal muscle tissue protein composition isfollowed by vacuum tumbling.
 7. The process of claim 5 wherein the pH ofthe aqueous basic solution is between about 11.0 and about 12.5.
 8. Theprocess of claim 5 wherein the pH of the aqueous composition of animalmuscle protein is between about 5.5 and 9.5.
 9. The process of claim 5wherein the salt added during step c) is sodium chloride.
 10. Theprocess of claim 5 wherein said food grade acid composition is citricacid and said food grade alkaline composition is sodium bicarbonate. 11.The process of claim 5 wherein the animal muscle tissue is taken fromthe group consisting of: i) fish animal muscle tissue, ii) shellfishanimal muscle tissue including shrimp animal muscle tissue, iii) poultryanimal muscle tissue including chicken animal muscle tissue and turkeyanimal muscle tissue, and iv) meat animal muscle tissue including beefanimal muscle tissue, pork animal muscle tissue and lamb animal muscletissue.
 12. The composition of claim 11 wherein the salt added duringstep c) is sodium chloride.
 13. The composition of claim 11 wherein saidfood grade acid composition is citric acid and said food grade alkalinecomposition is sodium bicarbonate.
 14. The process for forming aninjectable salted aqueous suspension of functional animal muscle tissueprotein composition for use during a food processing injection procedurewith at least one injection pathway wherein the salted aqueoussuspension of functional animal muscle tissue comprises sarcoplasmicproteins and myofibrillar proteins , said process comprising: A)comminuting animal muscle tissue to form comminuted animal muscletissue, B) mixing said comminuted animal muscle tissue with a food gradebase composition to solubilize anuimal muscle protein in an aqueousbasic solution of animal muscle protein having a pH between about 11.5and about 12.0, C) preparing an aqueous suspension of animal muscleprotein by mixing said aqueous basic solution of animal muscle proteinwith a food grade acid composition to form an aqueous suspension ofanimal muscle protein particulates having a pH between about 4.7 andabout 11.0, D) adding salt to the aqueous solution to form a saltedaqueous suspension of animal muscle protein composition includingsarcoplasmic proteins and myofibrillar proteins whereby said comminutedsalted aqueous suspension flows through each injection pathway during aninjection procedure without blocking an injection pathway, and E)comminuting said salted aqueous suspension of animal muscle proteinhereby to form the injectable salted aqueous suspension of functionalanimal muscle tissue protein composition including sarcoplasmic proteinsand myofibrillar proteins whereby said comminuted salted aqueoussuspension flows through each injection pathway during an injectionprocedure without blockiing an injection pathway.
 15. The process ofclaim 14 wherein membrane lipids are separated from said aqueous basicsolution of animal muscle tissue protein.
 16. The process of claim 14wherein the salt added during step c) is sodium chloride.
 17. Theprocess of claim 16 wherein said food grade acid composition is citricacid and said food grade alkaline composition is sodium bicarbonate. 18.The process of claim 25 wherein the animal muscle tissue is taken fromthe group consisting of: i) fish animal muscle tissue, ii) shellfishanimal muscle tissue including shrimp animal muscle tissue, iii) poultryanimal muscle tissue including chicken animal muscle tissue and turkeyanimal muscle tissue, and iv) meat animal muscle tissue including beefanimal muscle tissue, pork animal muscle tissue and lamb animal muscletissue.